Plasmodium gallinaceum: sporozoite activity in immune mosquito hemolymph.

Sporozoites of Plasmodium gallinaceum are relatively inactive in Hanks' balanced salt solution or in the hemolymph of the susceptible Aedes aegypti mosquito. They become agitated and very active in the presence of the hemolymph of the innately immune mosquito, Culex pipiens. Sporozoites from the latter are more infective in chicks than the former. This behavior is likely the result of stimulation or irritation by the adverse environment.